3) It was in "A Traitor is Found" that faulty execution equipment killed a number of witnesses in addition to the traitor it was supposed to; Queen Tamia, however, was one of the few to survive that particular plot twist.

I see:
traitor is found = faulty equipment != queen tamia

Depending on how you look at that; it's 3 clues and doesn't break my partially completed chart free. What is the forth?